Northeastern
Pacific blue whale calls are perhaps the best known blue whale
call to date. They generally consist of two parts, A and B.
The A call is a series of pulses (on the order of 1.5 pulses/s)
which often exhibits side-banding and the B call is a long
FM moan. A short (8s) upswept call (C) is occasionally seen
between A and B and Thompson et al. (1996) report a short,
sharp downsweep. These calls have been recorded from offshore
Vancouver Island B.C., Washington and Oregon, California and
off Mexico in the Gulf of California (reviewed in Rivers 1997),
and in the Eastern Tropical Pacific (Stafford 1996, 1997).